The invention involves a connection fitting for the attachment of oblong structures, for example of cables, hoses, tubes, corrugated hoses or the like, to an opening, in particular, to an opening or hole in a wall of a housing or the like, where the connection fitting has an attachment projection that projects axially in the plug-in direction, which is divided by slits into holding tongues running essentially in the axial direction, on the outer side of which holding projections are arranged which project radially outwardly and in the attachment position engage behind the edge of the opening when the mounting projection and its holding tongues are inserted into the opening. The mounting tongues have a shape that expands in the plug-in direction and correspondingly tapers in the withdrawal direction, on their attachment projections in their contact area, or they form a cone, so that the attachment tongues can be deformed in the radial direction during an axial movement of the connection fitting opposite to the plug-in direction. At a distance from the attachment projections, a sheath that has or forms a stopper is arranged which rests on the opening edge that lies opposite the edge of the opening that is engaged behind and which can be moved in the axial direction by reducing the distance to the attachment projections in order to generate a clamping force between the holding projections and the stopper.
A connection fitting of this general type is known from the U.S. Pat. No. 1,902,229. In this, the attachment projection has only two slits lying opposite each other and also smoothed out surfaces since the connection fitting consists of metal. The conical attachment projections are toothed in order to be able to press on the edge of the opening that is engaged behind. This means that at the latest during the attachment of this connection fitting, the edge of the opening is changed, which can be especially inhibitive to disassembly.
Furthermore, such an arrangement is unsuitable for a connection fitting in which the attachment projection consists of a synthetic material in a desired manner and for example, can be made in a cost-effective way in an injection molding process in large production quantities. In the reverse situation, directly for a synthetic material design of this type, there is the danger that the attachment projection is damaged by the hole edges and can be possibly pressed on hole edges that are not very precisely processed and thus, the axial movement that is necessary when affixing it is made more difficult or even stopped to the extent that a radial movement of the attachment tongues, to be caused by an axial movement, is prevented.
Therefore, the object for the invention is to create a connection fitting of the above-noted type which retains the advantages of a simple mounting ability by the latching of the attachment projection into an opening and the likewise simple bracing of an oblong structure through an axial withdrawal movement, without being impaired by the edge of the hole or in the necessary movements. In connection with this, it should be possible to also attach the connection fitting to an opening or hole, in which the edge that is grasped behind is imprecise or even notched.
To achieve this apparently contradictory object, the connection fitting defined at the beginning is characterized in that the sheath that has the stopper has a support that extends axially out from the stopper, and the support extends in the mounting position on the outer side of the retaining tongues of the mounting projection between the mounting projection and the inner wall of the opening that is engaged behind, and during an axial movement of the mounting projection and its attachment tongues, impinges a conical or tapering area of these attachment tongues and in this way, functions to press them together radially.
As opposed to the state of the art, where the sheath that forms a stopper is a union nut that has a ring-shaped flat front side that faces the hole or wall, a support is thus arranged on this front side in the solution according to the invention, which meshes into the opening and thus into the wall, i.e. lines this hole on the inside. This support is now used in order to impinge the attachment tongues in their conical area during the axial movement of the attachment projection opposite the plug-in direction, and to provide for pressing them together radially so that edges of the opening that are themselves damaged, notched, or sharp, do not impair these attachment tongues of the mounting projection and can not prevent their movements. Thus, in an advantageous way, a material can be selected for the attachment projection and its attachment tongues, which is oriented in the best possible way with the desired deformations during the affixing of an oblong structure and need not take into consideration the material of the wall in which the hole is located. In this way, a good flexible and resilient synthetic material can be applied, however, a manufacture out of metal is also conceivable. In an advantageous way, the connection fitting can thus be introduced as a simple plug-in fitting into a corresponding opening and then locked in it, and then an oblong structure that is introduced in it, for example, a cable with strain relief, is attached and clamped, such that the connection fitting can be withdrawn opposite the plug-in direction and in this way, the attachment projection can be pressed together radially, where the pressure force generating this radial movement, however, is applied completely or at least partially through the support that is provided according to the invention and extends into the opening, which allows a corresponding gentle impingement of the conical or tapering area of the attachment tongues.
For a fixed seat of the connection fitting in the assembly position within the opening, it is advantageous when the support can itself be expanded through the attachment tongues that can be pressed together radially by it and/or can be pressed against the inner wall of the opening at least locally in the mounting position. This results in not only a fixed seat, but also in a good security against twisting, which is most of all advantageous when the sheath that has or forms the stopper is able to be screwed on for its axial adjustment.
In this way, the radial expandability of the support can be supported by a corresponding material selection, especially however in that the support that projects in the axial direction on the stopper sheath and meshes in the assembly position into the hole, is divided by axially running slits, in particular open on the front side, into individual slide tongues. These slide tongues can thus be immediately firmly pressed when the connection fitting is braced, through the withdrawal movement of the attachment projection, on the inside of the opening or hole, and are in this way supported from the outside in. Thus, a fixed clamping of the entire connection fitting results in the opening and at the same time a correspondingly strong strain relief on the oblong structure, for example, on a cable or hose, is provided.
For a simple mounting and manufacturing, it is especially advantageous that the support and/or the slide tongues that form it are free of projections on the outer side. In a correspondingly simple manner, the support can be introduced into the opening or hole of a wall. Furthermore, after detaching the bracing, a simple disassembly is also possible. In addition, the production is simple, relative to an arrangement in which adjacent tongues must be provided with projections or recesses.
The support can therefore extend within a hypothetical sheath cylinder in the preliminary mounting position or relaxed position. Thus, it corresponds essentially to the common inner contours of openings or holes in housing walls, and can be easily introduced in them and after that, at least locally radially expanded, especially then when it is divided through axial slits into separate slide tongues that are open on the end.
The supports located on the stopper sheath can in the starting position of the clamping movement, extend to the retaining projections and have an entrance slope that acts together with a sloped surface of the mounting projections. In this way, the corresponding radial inwards movement of the attachment tongues having the attachment projections, which is supported by the entrance slope on the support or its slide tongues, readily begins immediately during a first axial return movement of the mounting projection. Especially by these entrance slopes, the surface pressing that occurs can also be reduced and an increased resistance by surface roughness can be avoided.
The support can have an axial dimension that corresponds to the axial expansion of the opening that is passed through by the attachment projection, at least for a fraction over half of it or completely, or it can have an axial dimension that exceeds this axial expansion. The support can thus line at least the largest part of the opening or hole in the usage position, and for certain application cases, however, may even project out over it on the inside. This is possible therefore, since the support also causes, in the axial movement of the connection fitting for its attachment, the radial movement of the attachment tongues, i.e. makes these movements for the most part independent of the opening.
At the same time, however, the support is itself clamped through this activation in the opening, so that it can also transfer the corresponding reaction forces to the attachment tongues. In the majority of cases, an attempt is made to make it so that the support and its slide tongues line the largest part of the inside of the opening, however, in an application of this same fitting to a wall having a smaller thickness, the attachment can also then occur when the support or its slide tongues extend beyond the inner edge of the opening that has a smaller dimension than this in the axial direction.
The number of slits on the support can correspond to the number of slits and the attachment tongues of the attachment projection. This results in a good reciprocal impingement and corresponding deformations during the clamping of the connection fitting.
An embodiment of the invention that is especially significant provides that the slits of the support and the slits of the attachment projection are set apart from each other in the mounting position in the circumferential direction and that on the attachment projections, guide elements or guide rails or the like are set up on the outside, which in the usage position fit into the slits of the support and mesh at least locally. In this way, during a reciprocal bracing under simultaneous performance of a rotational movement, a relative rotation occurs that prevents additional bracing is avoided. Should for example the axial movement of the attachment projection be caused to act against a first plug-in direction using a threading, a rotational movement must be performed which in the progression of the increasing clamping, opposes a larger and larger resistance. In this manner, under certain circumstances, the danger would result of a relative rotation of the attachment projection opposite the support, which is prevented by the reciprocal teeth between the guide components or guide rails on the attachment projections on the one side and the slits of the support on the other side. In this way, the slits of the support have an additional function, since they create a form fit between the support and the attachment projection in the circumferential direction via the guide components or guide rails.
An embodiment of the invention by which it is ensured that the attachment tongues, or even guide rails possibly provided on the outside of them, are not damaged by the edge of the opening that is engaged behind, and are prevented in their movement by this edge, can consist in that the free edge of the support or the slide tongues that form it impinge the mounting tongues and/or the guide rails on the outside in such a manner and affix it in the radial direction such that the outer circumference in the area of the edge of the opening to be engaged behind or that is engaged behind is equal to or in particularxe2x80x94preferablyxe2x80x94somewhat smaller than the circumference of this edge and that the slope angle of the mounting tongues in the area of the support and/or the entrance slope on this support have such an angle that during the axial movement of the attachment projection in the direction towards this openingxe2x80x94i.e. opposite its original plug-in directionxe2x80x94the radial pressing together of the attachment tongues is so large that they continue to remain contact-free or at least essentially free of friction on the engaged behind edge of the opening. It is also provided through the selection of the slope surfaces on the attachment projections of the attachment tongues or on the support for this, that not only for the beginning of the clamping movement, but also in its continued progression, in which the mounting tongues are pulled more and more back into the opening, so that the slope surfaces provided on the outside of them can be effective, in the sense of a radial deformation, and not get into such a contact with the edge of the opening that is engaged behind, such that interlocking or damage could result. Moreover, it is especially desired that also in this way, a direct contact between the attachment tongues or attachment projections and the opening or its opening edge is avoided.
For an axial movement of the attachment projection without a relative rotation of the sheath that has the stopper and thus the support that meshes in the opening, it is expedient when the connection fitting has on its surface or edge that faces away from the attachment projection, a radially projecting abutment or a collar which forms an abutment for a shifting component, which is arranged between this collar and the stopper of the stopper sheath and presses the stopper and this collar apart in the axial direction. By the pushing apart of the stopper on the one hand and the abutment or collar on the other hand, the stopper is pressed against a wall that has the hole and at the same time, the remaining part of the connection fitting is withdrawn opposite the plug-in direction, which results in the desired axial movement in the area of the attachment projection, through which the radial pressing together of the mounting tongues is caused. In this manner, various mechanisms for moving apart the stopper and the abutment or collar can be applied.
It can be practical when the tensioning component between the collar and the stopper is a spring, and in particular a compression spring, orxe2x80x94for a targeted or adaptable clamping force that is in many cases preferredxe2x80x94is a threaded sheath that can be rotated away from the stopper for the tensioning, acting together with the outer threads on the stopper sheath.
In the first case, the user must, when setting the connection fitting in the opening, simultaneously compress the compression spring and then achieve the desired clamping by releasing it, which leads to an automatic clamping which is prescribed by the force of the compression spring and thus is also limited. In the second case, the user can screw tighten the threaded sheath such that it is moved along the stopper sheath axially by its stopper, so that the unit that includes a stopper sheath and threaded sheath provides an increasing axial dimension. Also this then leads to the desired tension since the collar or the abutment is moved away from the opening on the connection fitting in this manner, which automatically results in the partial pulling in of the attachment projection into the opening that is grasped from behind by this attachment projection, with the resulting radial deformation of the attachment tongues. In this manner, the user is able to control, by turning the threaded sheath to a greater or lesser extent, how strong the clamping should be or how wide the radial deformation of the attachment tongues that form the attachment projection should go. This solution thus makes possible an improved adaptation to variously sized oblong structures. Directly for such a solution, it is especially advantageous when the stopper sheath with the support that meshes in the hole and the attachment projection of the connection fitting are secured against a mutual turning; even after a short tensioning movement, the support is namely clamped within the opening so that even the increasing turning of the threaded sheath can no longer carry along with it the stopper sheath in the direction of rotation, even when a greater and greater torque is applied to the stopper sheath. Furthermore, the friction occurring on the abutment or collar through the threaded sheath can also not carry it along in the direction of rotation.
The stopper collar and the attachment projection with the attachment tongues and attachment projections as well as guide rails arranged on them if necessary, can be a single piece and in particular, consist of plastic. This results in a cost-effective manufacture from a material which is elastic, i.e. can transfer a corresponding axial movement of the attachment tongues into a radial movement via its slanted or conical design. At the same time, a spring-back can occur during assembly. It would also be possible, however, to manufacture it out of metal.
The attachment projection can have catches or equivalent retaining components on the front side, which grasp inwards for the capture of the oblong structure and/or to support a seal that lies on the inside. Thus, such a seal lying on the inside can overlap on its front side and be pressed during clamping onto the oblong structure on the outside.
Into the stopper, from which the support extends out, an elastic ring, sealing ring or O-ring can be arranged at a radial distance from this support, or connected to a part of its cross-section in a ring groove or equivalent recess, which has a larger diameter than the support, i.e. functionally surrounds it concentrically. Thus, in the stopper area, a seal and a certain elastic compression can also occur, which additionally opposes a rotation of the sheath that has the stopper, when for the clamping, a screw connection that is made relative this sheath is performed.
On the whole, resulting from a combination of individual or several of the aforementioned characteristics and measures, is a connection fitting that can be mounted in a simple way by plugging it into an opening, such that within the opening a slide bearing is constructed which is pressed during clamping against the inside of the opening in the housing wall and in this way, causes a resistance against rotation, if the bracing for its part occurs through a rotational movement and a threading. In this manner, this effect can be increased by a sealing ring or O-ring that is located on the stopper. Additional guide components or guide rails on the outer sides of the attachment tongues functioning as clamping components can thus be guided in the axial direction into the slits of the support that forms the slide bearing such that a rotation, of the attachment projection as well, and thus of the entire connection fitting is prevented. The collar that functions as an abutment on the connection fitting can in this way be held fixed during such a tensioning or even during the detachment of this bracing through a threaded sheath, until the corresponding clamping is achieved within the opening.
A threading for a union nut that is immediately available on the connection fitting is thus avoided. Nevertheless, a comparison of various thickness or sizes of the wall that has the opening can be made. For a solution with a threaded sheath that can be turned in order to generate the tensioning force, an attachment grip is available. At the same time, all individual parts can be connected to each other so that they are captive and a special assembly tool is avoided. Furthermore, the conical area especially, which causes the radial clamping and the strain relief, is connected as a single piece with the actual connection fitting and the part of the connection fitting that has the abutment or the collar. This results in a correspondingly stable connection fitting.